Closed
Description
The following program panics:
package main
import (
"bytes"
"encoding/hex"
"io"
"log"
"os"
"golang.org/x/crypto/openpgp"
)
// An empty Keyring
type emptyKR struct {
}
func (kr emptyKR) KeysById(id uint64) []openpgp.Key {
return nil
}
func (kr emptyKR) DecryptionKeys() []openpgp.Key {
return nil
}
func (kr emptyKR) KeysByIdUsage(uint64, byte) []openpgp.Key {
return nil
}
var data = "9c3004303030300100000011303030000000000000010130303030303030303030303030303030303030303030303030303030303030303030303030303030303030"
func main() {
buf, err := hex.DecodeString(data)
if err != nil {
log.Fatalln(err)
}
md, err := openpgp.ReadMessage(bytes.NewBuffer(buf), emptyKR{},
func([]openpgp.Key, bool) ([]byte, error) {
return []byte("insecure"), nil
}, nil)
if err != nil {
log.Fatalln(err)
}
_, err = io.Copy(os.Stdout, md.UnverifiedBody)
if err != nil {
log.Fatalln(err)
}
if md.SignatureError != nil {
log.Fatalln("integrity check failed")
}
}with the trace:
panic: division by zero
goroutine 1 [running]:
math/big.nat.div(0x0, 0x0, 0x0, 0xc20803c570, 0x0, 0x5, 0x0, 0x0, 0x0, 0xc20803c570, ...)
/opt/go/src/math/big/nat.go:503 +0xcb
math/big.(*Int).QuoRem(0xc208020320, 0xc2080200e0, 0xc2080202e0, 0xc2080202e0, 0x1, 0x5)
/opt/go/src/math/big/int.go:224 +0xb6
math/big.(*Int).Mod(0xc2080202e0, 0xc2080200e0, 0xc2080202e0, 0xc2080202e0)
/opt/go/src/math/big/int.go:255 +0x15c
crypto/rsa.(*PrivateKey).Precompute(0xc208068000)
/opt/go/src/crypto/rsa/rsa.go:376 +0x1ba
golang.org/x/crypto/openpgp/packet.(*PrivateKey).parseRSAPrivateKey(0xc208040000, 0xc208066000, 0x22, 0x600, 0x0, 0x0)
/home/marebri/devel/go/src/golang.org/x/crypto/openpgp/packet/private_key.go:266 +0x520
golang.org/x/crypto/openpgp/packet.(*PrivateKey).parsePrivateKey(0xc208040000, 0xc208066000, 0x22, 0x600, 0x0, 0x0)
/home/marebri/devel/go/src/golang.org/x/crypto/openpgp/packet/private_key.go:234 +0x6c
golang.org/x/crypto/openpgp/packet.(*PrivateKey).parse(0xc208040000, 0x7f5e808d1bc0, 0xc208020080, 0x0, 0x0)
/home/marebri/devel/go/src/golang.org/x/crypto/openpgp/packet/private_key.go:103 +0x3f8
golang.org/x/crypto/openpgp/packet.Read(0x7f5e808d1b60, 0xc2080120e0, 0x7f5e808d1be8, 0xc208040000, 0x0, 0x0)
/home/marebri/devel/go/src/golang.org/x/crypto/openpgp/packet/packet.go:375 +0x152
golang.org/x/crypto/openpgp/packet.(*Reader).Next(0xc20803c330, 0x0, 0x0, 0x0, 0x0)
/home/marebri/devel/go/src/golang.org/x/crypto/openpgp/packet/reader.go:37 +0x10c
golang.org/x/crypto/openpgp.ReadMessage(0x7f5e808d1b60, 0xc2080120e0, 0x7f5e808d1b88, 0x68c0a8, 0x5f0860, 0x0, 0xc208062000, 0x0, 0x0)
/home/marebri/devel/go/src/golang.org/x/crypto/openpgp/read.go:101 +0x206
main.main()
/home/marebri/devel/lab/go/crypto/openpgp/issues/50eccec52/main.go:40 +0x285
goroutine 2 [runnable]:
runtime.forcegchelper()
/opt/go/src/runtime/proc.go:90
runtime.goexit()
/opt/go/src/runtime/asm_amd64.s:2232 +0x1
goroutine 3 [runnable]:
runtime.bgsweep()
/opt/go/src/runtime/mgc0.go:82
runtime.goexit()
/opt/go/src/runtime/asm_amd64.s:2232 +0x1
goroutine 4 [runnable]:
runtime.runfinq()
/opt/go/src/runtime/malloc.go:712
runtime.goexit()
/opt/go/src/runtime/asm_amd64.s:2232 +0x1
Found using gofuzz. You may assign this issue to me.